Update README to reference cl workflow and clarify build/config behavior

[NathanNeurotic]

Motivation

• Replace incorrect CI references with the actual cl workflow and align the documentation with the repository's workflow files.
• Avoid absolute claims about device availability and IRX loading by making configuration and device behavior conditional and beginner-safe.
• Document how local variant builds work via make list-variants instead of listing CI-only flags that do not apply.
• Address inline comments by correcting references and preserving explicit recovery and step-by-step guidance.

Description

• Replaced occurrences of "CI" with cl and updated the workflow reference to .github/workflows/cl.yml in README.md.
• Replaced explicit CI-only build flag examples with a description to run make list-variants and build each matrix entry, removing misleading flag lists.
• Rewrote several sections to emphasize that config file discovery and device availability are conditional on build flags and successful IRX loading, while preserving rescue instructions like R1 + START and mass:/RESCUE.ELF.
• Applied the edits to a single file, README.md, updating wording, examples, and the config search/build guidance to reflect verified behavior.

Testing

• No automated tests were run because this is a documentation-only change.

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Codex Task

[codacy-production]

Codacy's Analysis Summary

0 new issue (≤ 0 issue)
0 new security issue

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